PROJECT: Recharge Feasibility and Pilot project

Hermiston, Oregon

Since 1991, GSI personnel have assisted a group of farmers in eastern Oregon in assessing the feasibility of recharging the Columbia River Basalt aquifer underlying the Butter Creek Critical Groundwater Area located near Hermiston, Oregon. Without artificial recharge, these farmers will not be able to irrigate their land using these wells. The source of the recharge water is shallow alluvial groundwater that is available only in the wintertime. The study consisted of a detailed characterization of the basalt aquifer, assessment of recharge water and native groundwater quality, an evaluation of hydrogeologic factors influencing the rate of recharge water migration in the aquifer away from the ASR well, and a description of a pilot recharge project. The basalt groundwater system is strongly controlled by faulting and folding. A permit to conduct ASR testing was obtained and a pilot project is being conducted at two deep basalt wells. A key element of the project will be to assess whether the recharge water quality (shallow alluvial groundwater) can consistently meet regulatory criteria. The project is in its third year of operation; in 2008, approximately 1,100 acre-feet of water were stored.